This invention pertains to the field of control systems for scale model railroad layouts, and specifically to improvements in low-cost user throttle devices.
The rapid growth of the control of model railroad layouts by Digital Command Control, DCC, or other multiple train control schemes such as taught by Palmer in U.S. Pat. No. 4,335,381 and Lahti in U.S. Pat. No. 4,341,982 have increased demands for user input or control devices that are often termed xe2x80x9cthrottlesxe2x80x9d or controller units.
Since Command Control schemes permit concurrent multiple train operations with multiple persons controlling one or more locomotives or trains, it is usual for layouts to employ from a couple, to dozens of throttles when in operation. Complex layout control systems often employ many expensive throttles along with other system enhancements such as; expanded power boosters and fault control, signaling and occupancy detection, transponding, attached computers and even sound systems. Each of the controlled locomotives or control output devices attached to the layout has an addressable decoder device to detect the commands encoded and transmitted to it by the multiple train control system, and then executes the desired command, such as locomotive motor control etc.
A particular problem is creating multiple train control or command control systems where the cost of the control equipment is less than a budgetary constraint for novice users of these new technologies. Here a minimum system would be initially configured for train control with a single throttle. Addition of a second or more throttles is then a large extra expense to obtain the full benefits of multiple train operations.
In February 1992 at the Nuremburg Toy Fair, Marklin GmbH introduced the novel concept of the xe2x80x9cDelta Systemxe2x80x9d that was tailored to provide a compatible and less expensive control system, with reduced features, compared to their more complex earlier xe2x80x9cAC Digitalxe2x80x9d or xe2x80x9cMotorola/Trinaryxe2x80x9d digital system.
The Marklin Delta system can deliver a digital multiple train control system at a lower cost by employing an existing European style variable throttle alternating current (AC) power transformer or power pack. This provides both input power to operate a Delta 6604 digital control unit and the conventional variable 16-volt AC train control voltage of the transformer unit is used as a speed controller. In this way, the 6604 Delta module is added to a standard European 16-volt AC train control transformer unit to create a hybrid digital multiple train control system. In this hybrid system, reversal of direction is commanded by using the higher voltage AC pulse (up to about a 40 volt peak) that is normally used to reverse European 16-volt AC motored locomotives. The Delta 6604 control unit simply has 4 selectable locomotive addresses and two stop positions. Note that the 6604 unit has no inherent throttle capability but just acts to select one of a very limited set of four address numbers #24, #60, #72 and #78. The Delta 6604 controller has no other control features, but a second xe2x80x9cwalk-aroundxe2x80x9d 6605 passive Hand controller unit or throttle with a permanently fixed locomotive address #80 may be connected to the controller to provide speed and direction control for second train operation with just locomotive address #80.
The Delta system thus allows a low-cost multiple train control capability to be created but does not allow: expansion of user controllable functions such as lights or sound units in each locomotive, the selection of any address within the range configurable in any compatible locomotive decoders, the forming of consists (the linking or unlinking of multiple different address locomotives into a single controlled train address), or the use of a non-AC type of train control unit as the primary throttle. Additionally, the Delta 6604 is inoperable as a stand-alone control unit and has to have the European style variable AC power transformer added to create a functional system.
In contrast to Europe, the most common form of conventional, or non-digital, model train control in the United States are in fact variable voltage direct current (DC) power packs or throttles, where the power pack output polarity is used to control direction and the voltage level controls speed of DC motored locomotives.
A passive throttle interface has been provided as a fixed address #00 Analog throttle on the Wangrow Electronics xe2x80x9cSystem Onexe2x80x9d Command Station, introduced in 1994. In this application, a simple specific potentiometer or network of passive devices is attached via a dedicated cable to pins internal to the Command Station. This passive throttle then allows a user control of speed and direction for fixed address #00 (the address often used to describe the control of an NMRA Analog DCC or non-decoder equipped locomotive). This application offers no control capability other than speed and direction with the passive throttle, even though the System One command station itself supports advanced features such as function control, access to a full range of DCC addresses, and items such as formation and control of consists. Thus, this is a passive, very simple and limited throttle.
In 1993 Digitrax introduced the low cost xe2x80x9cChallengerxe2x80x9d DCC system where the user throttle was a CT4 hand controller with four rotary speed control knobs. This system used a novel combination of passive elements in the four control lines from the throttle to create different DC voltage levels that singly, and in combination, encoded four speed and direction channels, a mechanism to select from a limited subset of 16 possible DCC addresses (from #00 to #15), and a key to control locomotive lights, or function FO. Additional functions F1 to F12 and addresses above #15 are not accessible. The matching DB100 control unit is used to power the track, but is not operable without the CT4 throttle to provide control inputs from a user. This is a further example of a limited passive external throttle connected to a control unit. Again, this passive throttle does not access all the possible common features of DCC control systems, although the CT4 throttle is itself capable of very limited locomotive address selection.
Note that these last two passive throttles provide no power to the system, but rather are powered by them and have no alternative control utility such as a DC power pack may have when just controlling a conventional DC layout. By contrast, a command control or digital throttle type is considered active in that it has a control or communication interface that encodes digital data for transmission to the control system, and is not limited to signals conveyed by the simple voltage levels of a passive throttle.
A valuable improvement over the prior art is the creation of a multiple train control system that permits the use of DC or other conventional power packs as low cost conversion throttles, and that also offers augmented control features to these conversion throttles. This would overcome many of the limitations of the prior art, such as offering the ability to address the full range of possible locomotive addresses, control of functions and formation of consists, not possible with that prior art.
This invention improves on the prior art by allowing surplus or superseded older power packs or direct current control devices to become conversion throttles that then have simulated features associated with them that are comparable with the user interfaces of digital throttles.
Digital throttles perform at least similar functional speed and direction control of locomotives that older power packs do for conventional locomotives, but additionally, usually have at least a user interface with a locomotive address selection mechanism, and/or function controls and other advanced features. These extra features of the user interfaces of digital throttles are not an inherent, possible or native capability in older power packs or direct current control devices.
To gain this valuable user interface conversion or simulation capability, the user interface of a digital throttle is xe2x80x9cexportedxe2x80x9d or associated with a particular power pack or direct current control device that is then considered to be termed a conversion throttle. This association method allows a unique and arbitrary locomotive address selected by the digital throttle user interface, or other control capability to be given, or transferred to a conversion throttle. Once this transfer, or export, of a locomotive address is completed, the digital throttle may then be released from exporting and recall its prior address or be used to select a different address and control that next locomotive. Meanwhile the conversion throttle continues to control the exported locomotive address.
The key capability and value of this novel arrangement is that, during the export phase, the full control capability and features of the digital throttle performing the export is available to, and is associated with, the conversion throttle. This means the conversion throttle, which is normally limited to speed and direction control, can enjoy the benefit of having associated features like: address selection, function control, forming locomotive consists and other features that it has no native capability to perform.
In effect, all the control capabilities of a source digital throttle are transferred or mapped to the destination conversion throttle except for speed and direction control which is maintained by the speed and direction control setting of the destination conversion throttle. In the system the appropriate destination conversion throttle state or control information is loaded from the exporting or source digital throttle. This capability is very useful and practical since the majority of control of any active locomotive on the train layout is typically just speed and direction, which are always available as a native capability from the power pack or control device that is being converted. This is particularly the case for all model railroad layout control devices in the decades prior to the expanded features offered by modern multiple train control systems.
Accordingly, the majority of operating time for the conversion throttle is simply as a speed and direction control. The output leads of the conversion throttle are simply connected to the appropriate conversion interface in the system and the control output voltages of the conversion throttle are measured and calculated as the desired speed and direction. This information is then combined within the control system with the previously exported and associated (locomotive) state information to then control units on the layout. A digital throttle is thus not burdened with any tasks for the majority of the time when the conversion throttle is just controlling speed and direction. The export of control information to the conversion throttle can be viewed as a temporary transfer of the user interface of a digital throttle to augment the user interface and state information of a particular conversion throttle. While this transfer is in effect, it is possible to select any desired locomotive address, form consist links and unlinks of multiple locomotives in a train, as well as offer any other complex capabilities that the digital throttle may possess. Units controlled on the layout by throttles need not only be mobile locomotives. For example, a static digital scale-model crane with functioning boom, winch etc. can be controlled using the locomotive speed, direction and function control capability.
If temporary control of a function is needed for a conversion throttle controlled locomotive, for example a sound function actuation to blow the whistle, it is possible for the digital throttle to be briefly exported again to the particular conversion throttle to offer this control capability.
Note that when the digital throttle is used in this way it can xe2x80x9cimportxe2x80x9d or reload from somewhere in the system the present state information for the conversion throttle and only change the state of a feature requested by direct input from the user interface. In this manner the changing or export of the locomotive address to a conversion throttle can be differentiated from the actuation or modification of any other control features. This allows a selective and orderly access to any desired set of conversion throttle features from any other digital throttle with export capability that may be connected to the system. This distributes and enables powerful conversion throttle control throughout the whole system.
While a digital throttle is importing, modifying a control feature and then re-exporting this changed information to a conversion throttle, it is sensible for the state of any prior locomotive that the digital throttle may have been controlling to be saved and then automatically restored when conversion throttle export activity is completed. The duration of external control influence on a conversion throttle may be distinctly set by user action or automated by a mechanism such as a timeout or similar action.
Obviously the needed state information for any conversion throttle resides within the control system or even a digital throttle, since it cannot be embedded in the pre-existing power pack or direct current control device that is to be used as a conversion throttle. The contribution that the power pack makes to the conversion throttle synthesis is simply its native speed and direction control capability.